It seems that no matter what, I keep coming back to the Unity user interface. After a couple of weeks of using the MATE user interface, I just had to move back to Unity.
I really liked the experience I got with MATE, yet it lack something that Unity gives me. It's not something tangible, it's mostly my personal taste. I do recommend MATE as an option, yet personally I prefer running Unity. The major change I make to the stock setting, is using the Numix theme and circular icons.
Personally, no other user interface quite fits what I want my desktop to work and feel quite as well as Unity does. My two other favorite user interfaces, MATE and Cinnamon simply don't work as well for me.
In a way, this is way I like GNU/Linux. I like to have my choice of how my OS works, and how it looks. My personal choice is Ubuntu running Unity, though I also like and recommend Linux Mint running Cinnamon. I haven't used Mate on Linux Mint, yet I do like it and recommend it on Ubuntu.
In a way, Ubuntu gives me all what I want and like on my OS. It runs all the apps I both love, and the ones I need to keep in touch with family and friends. Most importantly, it does it in a way that doesn't intrude with how I do things.
When I moved away from Windows, I never could have imagined how much I'd come to like the experience of using GNU/Linux. Most importantly, the level of choice that comes with it. In more than one way, I've always enjoyed computers and software. Most importantly, how they allow people to come together in ways most people don't give a second thought.
Computers, along with smart phones, can be powerful tools to build communities by helping people together around what they love, hate, or whatever they are concerned about. Used correctly, they empower the people.
Most importantly, this power can be multiplied by FLOSS. That's why I moved to Ubuntu on my laptop, and Android for my smart phone.